This invention relates to an electric guitar and, in particular, to an electric guitar which is equipped with a tremolo bridge and a piezo pickup. In the art, when the strings are clamped on the guitar bridge, it is called a locking tremolo.
A known electric guitar equipped with a tremolo bridge 10A is shown in FIGS. 13-16. The guitar strings are fixed between the guitar neck nut and the tremolo bridge 10A, which has a bridge saddle part, and is located on the body surface of the guitar for the purpose of preventing the guitar from becoming out-of-tune at the time of performing with a tremolo.
The tremolo bridge 10A of the known guitar comprises a base plate 11, which is pivotable for swinging motion on the surface of the body, and a bridge saddle 31A, which is held by base plate 11 for maintaining the guitar strings in a tunable state. In an electric guitar which is equipped with a tremolo bridge, it is possible to effectively carry out both intonation adjustment or string adjustment for adjusting the length of the cord and fine tuning for the adjustment of the tension (pitch) of the cord. As compared with a tremolo bridge which does not lock, the locking type can reduce any possibility of out-of-tune performance with a tremolo and, at the same time, to increase the amount of tune change during the tremolo performance.
The base plate 11 of the tremolo bridge shown in FIGS. 13-16 has a forward facing, front knife edge 12, which serves as an installation part for the base plate on the body surface of the guitar. A stud bolt 13 engages the knife edge 12 and is affixed to the body surface. A stud fixing bolt 14 and an anchor 15 for the stud bolt are provided in the guitar body. An opening or groove 16 extends along the length of the saddle body for allowing movement of a rotatable adjustment bar 47 for front and rearward movement of the bridge saddle 31A of each string. An upstanding arm receptacle 18 is provided for a tremolo arm 17. An installation member 19 installs the bridge saddle 31A on the base plate 11. A plate spring 21 biases from below against the rotatable adjustment bar 47 of the bridge saddle 31A. A tremolo block 22 is beneath the spring 21. Tremolo springs 23 bias the tremolo block 22 to return from tilting. A bracket 24 fixes the tremolo springs 23 on the guitar body, and screws 25 fasten the plate 24 to the guitar body.
When the tremolo arm 17 is shifted inward in the direction of the guitar body, the base plate 11 swings against and around the stud bolt 13, which acts as a fulcrum, in opposition to the return direction force of the tremolo springs 23. See FIG. 16. As a result, the tuning of the chord pitch of the guitar can be changed, thereby providing a tremolo effect for a modification of the sound range of the tremolo.
In addition, the bridge saddle 31A shown in FIGS. 13-16 comprises a saddle holding member 32A and a main saddle body 41. The main saddle body 41 is held to be rotatable in the front-and-back direction on the saddle holding member 32A about an axle 42 defining an axis of rotation. A cut or groove 33A in the saddle holding member 32A, shown in FIG. 14, is provided for the installation of the saddle holding member 32A on the base plate 11 to allow the member 32A also to move forward and back on the base plate 11. A fixing bolt 34A passes through a metal washer 35A, and, they are above the saddle cut 33A and fasten the saddle 31A, and an opening 36A for accommodating the front part of the main saddle body 41 allows it to move slidably with respect to base plate 11, as seen in FIG. 15.
The length adjustment of the cord S or its so-called adjustment or intonation harmonic adjustment can be carried out by loosening the fixing bolt 34A and moving the related members, including the saddle holding member 32A and the main saddle body 41, etc. back and forth in the direction of the cord or string S.
A string receiving part 43 in the main saddle body 41 has a rearwardly and downwardly curved surface at the front of the main saddle body. A concavity 44 for fixing the string, a block 45 in the concavity for string fixing, a string fixing bolt 46 for holding the string fixing block are provided. A rotatable adjustment bar 47 for the saddle, and a fine tuning bolt 48, which is in contact with the adjustment bar 47 for rotating the main saddle body 41 by its up and down movement, are also provided.
If the tip of the fine tuning bolt 48 is moved downward by rotating the bolt, the adjustment bar 47 is pressed downward against the bias of the spring 21 and the main saddle body 41 rotates in a backward direction (in the clock-wise direction in FIGS. 15(A) and 15(B)) with the axle 42 as the center of rotation so as to move from the state shown in FIG. 15(B) to the state shown in FIG. 15(A).
If the fine tuning bolt 48 is rotated to move its tip upward, the adjustment bar 47 moves upward, with the main saddle body 41 rotating against the bias of the spring 21 in a frontward direction (in the counter-clockwise direction in FIGS. 15(A) and 15(B)) and with the axle 42 serving as the center of rotation so as to move from the state shown in FIG. 15(A) to the state shown in FIG. 15(B).
The fine tuning of a specific cord or string can be carried out in this manner. Thus, the main saddle body 41 is rotated in a backward direction when the tension (pitch) of the string is to be increased and the main saddle body 41 is rotated in the frontward direction when it is to be decreased.
Because the string receiving part 43 of the main saddle body 41 has a curved surface in the above described structure, the cord S always contacts the bridge saddle 31A at the same position or, to be specific, at a position Z at the top of the axle 42 of the main saddle body 41. As a result, the contact position Z does not move in the string direction X when the main saddle body 41 rotates. Accordingly, the string length (the distance between the contact position Z for the cord S with the bridge saddle 31A and the contact position with the nut portion at the opposite neck end of the guitar) does not change during fine tuning. Since the string remains in a tightened state, moreover, the harmonic tuned state of the cord S can be maintained.
On occasions, a guitar is provided with a piezo pickup disposed in the bridge. The sound collected by the piezo pickup is used for increasing the electric amplification or for collecting high frequency sound, thereby producing natural acoustic sounds in a folk guitar with a resonant trunk. In this system, a piezoceramic is utilized for the pickup. As compared with a conventional magnetic pickup system wherein electric current is generated in the pickup by vibrations of the strings, which act as magnetic material, the piezoceramic system generates an electric current or voltage through the contraction and elongation of a piezo ceramic by the string vibrations acting as a pressure signal. When a piezo pickup is used, therefore, it becomes possible to pickup the vibrations of a nylon string, etc. which is not of a magnetic material. This is not possible with systems using magnetic pickups.
An adjustment mechanism for obtaining the sound desired by the performer, for example, a reduction in excessive high range, by accommodating an equalizer at the control part, can be provided in a guitar having a piezo pickup.
When a piezo pickup is accommodated in a folk guitar having a resonant trunk, a bar-shaped piezo pickup can be inserted and fixed between a bridge saddle made of plastic and a base plate made of wood as the bridge structure is simple and the position and the height of the bridge are basically fixed.
In an electric guitar or bass guitar having a bridge or tremolo made of metal (not of the locking tremolo type as mentioned earlier), it becomes necessary to fix a plurality of small piezo pickups at the contact part with the bridge saddle, one for each string, because the bridge saddle is divided for the strings, making it necessary to cope with the changes in height or position. To enable this piezo pickup to function satisfactorily, however, it becomes necessary to fix the entire body without obstructing the compression or elongation of the piezo pickup. Accordingly, it has not been possible to provide such guitars that are equipped with piezo pickups with a tremolo bridge.